Rolls of household film such as are commonly sold in a dispensing carton through the grocery trade, are customarily manufactured with a cling or adhesive surface character in order to enhance the functionality of the film as a wrapping. This creates a need for a roll starting feature since the leading edge of the roll has a tendency to block intimately against the underlying layer in a manner whereby it is difficult to locate or find the edge, and difficult to peel it away to start the roll. Roll starting means or convenience features as have been used or proposed in the past, however, have oftentimes not been entirely satisfactory from a manufacturing standpoint, or because of poor or inadequate functionality.
Referring to certain specifics, it has been a common expediency to employ incremental lengths of adhesive tape as a starting feature. The tape is folded upon itself to provide a grasping end, and the opposite end of the tape is fastened adhesively to the film. It has been a problem, however, to reliably or faultlessly register the tape with the leading edge of the roll at high manufacturing speeds. Also the tape has a tendency to tear the film since it doesn't lift the edge evenly across the entire width of the roll.
An embossed pattern may also serve to distinguish the edge of the film, and reduce blocking or sticking of the edge to the underlying layer, such as to serve the function of a roll starting feature. Embossing the film at high speeds, however, is difficult since the film is relatively fragile and susceptible to breaking upon repeated contact with the embossing plate. Maintaining adequately precise temperature control is also difficult since if the plate is too hot, it may excessively thin the film causing extreme proneness to tear propagation, whereas if it is too cold, the embossing may not be distinct enough to serve as a functionally good starting feature.
The leading edge of the film may also be coated to make it less likely to block and the coating can be pigmented to easily identify the leading edge. However, the foreign substance or coating that is used must meet certain applicable government regulations since household wrapping materials are frequently used to preserve food. Moreover, the coating must survive extreme warehouse storage temperatures, while maintaining its functionality, and must be compatible with application to the film at high speed. So far as is known, the art has not heretofore developed a commercially successful coating of this type for household films.
Accordingly, it would be of advantage to the art if there were available a roll of household film having an improved means for conveniently identifying and grasping the leading edge of the roll, such as to start a new roll from a standard dispensing carton.
It would be of further advantage if the design of such convenience feature were compatible with the high speed production of the film in roll form.
It would be of still even further advantage if such convenience feature in addition to its grasping and identifying function, effectively if not altogether eliminated the problem or the tendency of the leading edge of the roll to block against the underlying film layer, such as under severe and protracted warehouse temperature conditions.
It would be of yet even further advantage if such convenience feature in addition to some or all of the above noted characteristics, would comprise an effective deterrent to the tendency of the edge to tear propagate such as from notches or flaws unintentionally formed in the edge in manufacturing the roll.